Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS5846669 A
Publication typeGrant
Application numberUS 08/586,595
Publication dateDec 8, 1998
Filing dateJan 16, 1996
Priority dateMay 12, 1994
Fee statusLapsed
Publication number08586595, 586595, US 5846669 A, US 5846669A, US-A-5846669, US5846669 A, US5846669A
InventorsEugene S. Smotkin, Thomas E. Mallouk, Michael D. Ward, Kevin L. Ley
Original AssigneeIllinois Institute Of Technology
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Hybrid electrolyte system
US 5846669 A
Abstract
A hybrid electrolyte system for fuel cells and other electrochemical reactors comprising an acid electrolyte, a base electrolyte, and a proton permeable dense phase separating the acid electrolyte from the base electrolyte.
Images(3)
Previous page
Next page
Claims(7)
We claim:
1. A hybrid fuel cell comprising:
a proton permeable dense phase having an anode facing side and a cathode facing side;
an anode electrode disposed on said anode facing side of said proton permeable dense phase;
a cathode electrode disposed on said cathode facing side of said proton permeable dense phase;
an acid electrolyte disposed between said anode electrode and said proton permeable dense phase; and
a base electrolyte disposed between said cathode electrode and said proton permeable dense phase.
2. A fuel cell in accordance with claim 1, wherein said dense phase comprises a metal hydride.
3. A fuel cell in accordance with claim 2, wherein said dense phase comprises palladium hydride.
4. A fuel cell in accordance with claim 1, wherein said acid electrolyte comprises an acid-containing matrix material.
5. A fuel cell in accordance with claim 4, wherein said acid-containing matrix comprises concentrated phosphoric acid in a silicon carbide matrix.
6. A fuel cell in accordance with claim 1, wherein said base electrolyte comprises an alkali-containing matrix.
7. A fuel cell in accordance with claim 6, wherein said alkali-containing matrix comprises concentrated potassium hydroxide in a potassium hexatitanate matrix.
Description
CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part patent application of co-pending patent application having Ser. No. 08/241,647, filed 12 May 1994, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a hybrid acid/base electrolyte system for fuel cells and other electrochemical reactors operating in a temperature range up to about 300 C. The primary application for this invention is in fuel cells which are electrochemical devices that convert chemical energy associated with fuels, such as hydrogen or alcohols, into electricity. Other applications for this invention include use in electrochemical reactors for the synthesis of industrially important chemicals such as aldehydes and carboxylic acids.

2. Description of Prior Art

Electrochemical devices, such as fuel cells, comprise an electrolyte, an air (or oxygen) electrode, and a fuel electrode. Alkaline fuel cells and phosphoric acid fuel cells constitute relatively mature forms of existing fuel cell technology. The main advantages of alkaline fuel cells arise from the excellent electrochemical properties of alkaline electrolytes. The electrode reaction kinetics for oxygen reduction are much better in an alkaline electrolyte (for example potassium hydroxide) as compared to an acid electrolyte (for example phosphoric acid). See, for example, Hirchenhofer, J. H., Stauffer, D. B., and Engleman, R. R., Fuel Cells --A Handbook (Revision 3) DOE/METC-94/1006, January 1994. The use of an alkaline electrolyte also can eliminate the need for expensive noble metal catalysts. Non-noble metal catalysts, such as carbon-supported transition-metal macrocyclics and their derivatives are effective oxygen reduction catalysts below about 80 C. Raney alloys, such as very high surface area nickel stabilized against recrystallization by titanium, also are good oxygen reduction catalysts for operation at temperatures between about 200-260 C. The highest catalytic activity ever reported for oxygen reduction was obtained using a heat-treated cobalt tetraphenyl porphyrin deposited on high surface area carbon (Fuel Cell Systems, (Eds. Blomen, L. J. M. J., and Mugerwa, M. N.), Plenum Press, New York, 1993, Chapter 2: pp. 42-52, 63-69, Chapter 3: pp. 88-97, p. 110, Chapters 7, 8, 11).

Potassium hydroxide represents the alkaline electrolyte of choice. Potassium hydroxide possesses higher conductivity than sodium hydroxide and the conductivity of concentrated aqueous potassium hydroxide increases rapidly with temperature. Oxygen electrode performance improves with concentration (Appleby, A. J., and F. R. Foulkes, Fuel Cell Handbook, Krieger Publishing Co., Malabar, Fla., 1993, Chapters 8, 10, 11, 12, 13, 16) and increase in alkali concentration also permits fuel cell operation at lower pressures. At close to ambient temperatures, the optimum electrolyte concentration is about 6N (27 wt. %). At higher temperature, concentrations as high as 12N (46 wt. %) can be used. The upper temperature limit for alkaline electrolyte use is about 260 C., which was the temperature employed by alkaline (75-85 wt. % potassium hydroxide) fuel cells, using pure H2 and O2, used in the Apollo missions.

The only real disadvantage of alkaline electrolytes is the reaction of alkaline electrolytes with CO2 to form carbonate, which degrades fuel cell performance drastically. This harmful reaction interferes with oxygen reduction kinetics in that it reduces OH- concentration, causes an increase in electrolyte viscosity reducing diffusion coefficients, reduces oxygen solubility, causes electrode degradation due to carbonate precipitation in electrode pores, and reduces electrolyte conductivity. Historically, therefore, alkaline fuel cells have used purified hydrogen fuel, and the direct use of organic fuels and impure (CO2 -containing) hydrogen has not been viable.

For operation at temperatures up to 200 C., phosphoric acid is the acidic electrolyte of choice. However, use of an acid electrolyte, in contrast to an alkaline electrolyte, essentially limits the choice of electrocatalyst to a noble metal catalyst. Current phosphoric acid fuel cell technology uses a 100% concentrated phosphoric acid electrolyte and noble metal catalysts for both fuel cell electrodes.

U.S. Pat. No. 4,443,522 teaches a fuel cell comprising spaced apart ion permeable membranes in a fluid receiving chamber, which membranes divide the chamber into adjacent cathode and anode compartments and, thus, establish acid-base interfaces between the compartments. The cathode is disposed in an acid electrolyte solution in the cathode compartment and the anode is disposed in a base electrolyte solution in the anode compartment. However, the ionexchange membranes dividing the chamber into adjacent cathode and anode compartments are not of a type which readily permits the conversion of alcohols into electricity, such as in a direct hydrocarbon fuel cell, without crossover of at least a portion of the alcohol fuel from the anode side to the cathode side of the fuel cell with the resultant deleterious consequences.

U.S. Pat. No. 5,318,863, U.S. Pat. No. 5,350,643, U.S. Pat. No. 4,894,301, U.S. Pat. No. 5,162,166, U.S. Pat. No. 4,988,583, and U.S. Pat. No. 4,828,941 teach various means for separating the anode and cathode of a fuel cell. In particular, the ' 863 patent teaches the use of a Nafion separator/membrane; the ' 643 patent and the ' 583 patent teach the use of solid polymer electrolyte membranes; the ' 301 patent teaches the use of a proton conducting electrolyte; the ' 166 patent teaches the use of an electron insulating/ion conducting electrolyte; and the ' 941 patent teaches the use of a CO2 -permeable anion exchange membrane electrolyte. U.S. Pat. No. 4,981,763 teaches a fuel cell comprising a pair of electrodes, a reaction layer positioned between the electrodes, and an electrolyte layer interposed between confronted reaction layers and holding therein an electrolyte for transmission of ions produced by the electrochemical reaction. All these patents suffer from one or more drawbacks; Nafion and other said polymer electrolytes are permeable to methanol and are inadequate for fuel cell use; other solid state electrolytes have inferior proton/ion conductivity for low temperature use and/or are CO2 permeable.

U.S. Pat. No. 5,252,410, U.S. Pat. No. 5,272,017, and U.S. Pat. No. 5,132,193 all teach the use of Nafion for separation of the anodes and cathodes of the respected fuel cell assemblies. However, Nafion as stated previously is known to be permeable to organic fuels such as methanol and, thus, is not suitable for use in a fuel cell or other electrochemical device which utilizes methanol as one of the reactants.

SUMMARY OF THE INVENTION

It is an object of this invention to provide an electrolyte system for fuel cells and other electrochemical reactors which combines the best features of alkaline fuel cells and phosphoric acid fuel cells. It is an object of this invention to provide an electrolyte system suitable for use in a fuel cell or other electrochemical device which allows proton transfer through the electrolyte system but prevents crossover of larger chemical species from one electrode side to the other electrode side of the fuel cell.

These and other objects of this invention are achieved by a hybrid electrolyte system for fuel cells and other electrochemical reactors comprising an acid electrolyte, a base electrolyte, and a dense phase separating the acid electrolyte from the base electrolyte. The dense phase separating the acid electrolyte from the base electrolyte is critical to the successful operation of the hybrid electrolyte system in accordance with this invention in that it is permeable to hydrogen, all the while being impermeable to larger chemical species including organic molecules. In this manner, separation of the said electrolyte from the base electrolyte is maintained and the crossover of hydrocarbon fuels, such as methanol, from the anode side to the cathode side of the fuel cell is prevented.

More particularly, the electrolyte system of this invention is a composite comprising a dense proton permeable phase, such as palladium hydride, which separates an alkalicontaining matrix, for example concentrated potassium hydroxide in a teflon-bonded potassium hexatitanate matrix, or circulating alkali electrolyte, from an acid-containing matrix, for example concentrated phosphoric acid in a teflon-bonded silicon carbide matrix. This electrolyte system enables separate compartmentalization of the air (oxygen) electrode with an alkaline electrolyte and the fuel electrode with an acid electrolyte, respectively, while still maintaining the integrity of the fuel cell system.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and objects of this invention will be better understood from the following detailed description taken in conjunction with the drawings wherein:

FIG. 1 is a schematic diagram of a hybrid acid/base fuel cell electrolyte system in accordance with one embodiment of this invention;

FIG. 2 is a diagram showing the effect of various preparative methods of platinum/palladium/platinum barriers on H2 /O2 fuel cell performance; and

FIG. 3 is a diagram showing the effect of acidic versus basic electrolyte in the cathode compartment of a hybrid electrolyte test system.

DESCRIPTION OF PREFERRED EMBODIMENTS

The critical feature of the electrolyte system of this invention is the simultaneous use of both an acid electrolyte and a base electrolyte which is made possible by the presence of a dense phase, such as a foil of proton permeable material which physically separates the acid and base to the electrode compartments where they are most beneficial to electrochemical performance. The main advantages of alkaline fuel cells due to the electrochemical properties of alkaline electrolytes have already been discussed hereinabove. In particular, the electrode reaction kinetics for oxygen reduction are much better in an alkaline electrolyte versus an acid electrolyte. The use of an alkaline electrolyte allows for the use of a variety of metal catalysts, both noble and non-noble metals. In contrast thereto, the use of an acid electrolyte essentially limits the choice of electrocatalyst to a carbon-supported noble metal catalyst. However, due to the reaction of the alkaline electrolytes with CO2 to form carbonate which degrades fuel cell performance, alkaline fuel cells are generally restricted to the use of purified hydrogen as a fuel; the direct use of organic fuels and impure hydrogen is not considered viable.

The innovated approach of the electrolyte system of this invention is the use of tailored electrolyte environments on each side of a hydrogen-permeable barrier for the respective electrode reactions, namely alkali (for the cathode) to take advantage of superior oxygen reduction kinetics, and acid for the anode to take advantage of its CO2 -rejection properties. Although alkaline fuel cells possess rapid oxygen reduction kinetics, and the use of non-noble metal catalysts is feasible, the electrolyte carbonation problem currently restricts alkaline fuel cells to the use of pure H2 and O2. The hybrid electrolyte system of this invention enables use of an alkaline environment for the cathode because the barrier between the cathode and the anode prevents carbonation from CO2 produced at the anode. The dense phase separating the cathode from the anode permits only the transport of protons and, thus, the alkaline electrolyte never "sees" the anode and the fuel oxidation products produced there. As a result, this hybrid electrolyte system permits the direct electro-oxidation of organic fuels or impure H2 at the anode in an acidic environment, while the oxygen reduction reaction is accomplished in a basic electrolyte. The hybrid electrolyte system of this invention, thus, enables a fuel cell device with higher cell potential (or less cell overpotential/voltage loss) for a given current density versus an acid-based electrolyte fuel cell. Operations at temperatures around 200 C. with appropriately pressurized and concentrated acid and alkali electrolytes insure that ohmic overpotential developed by the hybrid acid/base fuel cell is maintained sufficiently low and enhanced cathode kinetics insures superior fuel cell characteristics, that is current-voltage performance, versus known phosphoric acid fuel cells.

The alkaline fuel cell is the most efficient of all fuel cells and, as such, is one of the most attractive fuel cell systems for electric vehicle applications because of its advantages of high energy efficiencies/power densities, and the use of non-noble metal catalysts. The major challenge, of course, is the completely removed CO2 and prevent the effects of carbonation. For both space and terrestrial applications, the use of alkaline fuel cells, thus, is presently limited to the use of pure H2. The CO2 removal problem, however, is greatly diminished in the hybrid fuel cell of this invention compared to alkaline fuel cells because only CO2 removal from the oxidant is required, even if organic fuels or impure hydrogen are oxidized at the anode. In short, fuel cells utilizing the hybrid acid/base electrolyte system of this invention allow the use of alkaline electrolytes for the direct electrochemical oxidation of organic fuels, either for electricity production or chemical synthesis, and for the direct electrochemical oxidation of impure hydrogen (containing CO2), obviating the need for scrubbing CO2 removal processes required by known devices.

FIG. 1 is a schematic diagram of a hybrid electrolyte system in a fuel cell configuration in accordance with one embodiment of this invention. As shown, hybrid fuel cell 10 comprises a dense phase proton permeable material 17 separating acidic electrolyte-containing matrix layer 15 from basic electrolyte-containing matrix layer 16. Adjacent to the face of basic electrolyte matrix layer 16 facing away from dense phase proton permeable material 17 is electrocatalyst layer 14, adjacent to which is porous gas diffusion cathode 11. Similarly, adjacent to the face of acidic electrolyte matrix layer 15 facing away from dense phase proton permeable material 17 is electrocatalyst layer 13, adjacent to which is porous gas diffusion anode 12.

By the term "dense phase proton permeable material" we mean a material which is permeable to protons but impermeable to chemical species larger that atomic hydrogen. In accordance with a preferred embodiment of this invention, said dense phase proton permeable material comprises a foil of a metal hydride. In accordance with a particularly embodiment of this invention, said dense phase proton permeable material comprises palladium hydride.

In accordance with one preferred embodiment of this invention, the acid electrolyte is disposed within a matrix material. In accordance with one particularly preferred embodiment of this invention, the acid-containing matrix material comprises concentrated phosphoric acid in a silicon carbide matrix.

Similarly, the base electrolyte in accordance with one embodiment of this invention is also disposed within a matrix material. In accordance with one particularly preferred embodiment of this invention, said base-containing matrix comprises concentrated potassium hydroxide in a potassium hexatitanate matrix. It will be apparent to those skilled in the art that acids and bases which are normally employed in conventional fuel cells may be employed in the hybrid electrolyte system of this invention.

Although the problem of CO2 removal is greatly diminished in a hybrid fuel cell employing the hybrid electrolyte system of this invention when compared to conventional alkaline fuel cells in that only CO2 removal from the oxidant (cathode) side of the fuel cell is required. For example, if air is used as the oxidant gas, atmospheric CO2 must be removed by way of scrubbers or other processes, or the effects of electrolyte carbonation must be overcome by circulating the alkaline electrolyte. Although dense phase proton permeable material 17 prevents CO2 produced at the anode from carbonating the alkali on the cathode side of dense proton permeable material 17, it does so at the cost of additional impedance due to the bulk of dense phase proton permeable material 17 and the two additional interfaces created between the acid and dense phase proton permeable material 17 and the base and dense phase proton permeable material 17, respectively.

FIG. 2 shows the effect of various barrier preparation methods on H2 /O2 fuel cell performance. By activating the surfaces of dense phase proton permeable material 17 comprising, for example, palladium hydride with a catalytic material such as platinum, these interfacial impedances are significantly reduced so as to allow the passage of high current fluxes. Reduction of the thickness of dense phase proton permeable material 17, increase in operating temperature, and increases in the interfacial area available for proton exchange between dense phase proton permeable material 17/acid and dense phase proton permeable material 17/base, respectively, increases the current fluxes that can be passed through the electrolyte system to provide commercial viability.

EXAMPLE

We have acquired data on the use of a hybrid acid/base electrolyte system of this invention in a test fuel cell. In the test cell, a 25 micron foil of palladium modified on both sides by electrochemically deposited platinum was used as the proton permeable material. The foil was hot-pressed to one side of a Nafion 115 polymer membrane which serves as an acidic electrolyte. The other side of the proton exchange membrane was interfaced with a layer of electrocatalyst. The electrocatalyst was commercially obtained carbon supported-platinum. The test cell consisted of two compartments sealed from each other, an upper compartment open to air that could be filled with a liquid electrolyte of either acid or base, and a lower compartment with inlets and outlets for delivery of vapor phase fuel. The upper compartment was used to contain the cathode, which, for these experiments, was a high surface area platinum gauze electrode which rested upon the teflon-base of the upper compartment. A precise volume of liquid electrolyte (20 ml) was filled into the upper chamber, creating a liquid meniscus at the air/liquid/electrode three phase interface. The constant electrolyte volume also fixed the current path length from the meniscus, where most of the oxygen reduction occurs, to the palladium barrier. Pure oxygen was continuously bubbled at a flowrate of 300 ml/min into the liquid electrolyte using a capillary tube. Purified hydrogen, humidified at 80 C., was delivered to the lower compartment at a flowrate of 300 ml/min. The high surface area platinum electrocatalyst exposed to the fuel served as an anode.

Two experiments were performed with the cell temperature maintained at 80 C., one with 0.5M sulfuric acid in the upper compartment and one with 1M potassium hydroxide. Current-voltage (I-V) curves were measured potentiostatically for both fuel cells. Typical results are shown in FIG. 3. The primary observation of the experiment was that the open circuit voltage (OCV) for the hybrid cell containing alkali in the upper compartment was invariably higher than for the cell containing acid, typically by 60 mV, indicating superior kinetics for the oxygen reduction reaction in base. At low fuel cell currents, the current-voltage performance for the base-containing cell was superior. Because the two systems investigated directly compare the relative fuel cell performance of an acid/palladium/acid system versus a base/palladium/acid system, it can be concluded that less activation polarization (voltage loss) is developed by the hybrid acid/base fuel cell system compared to conventional fuel cell systems.

While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3522095 *Jan 14, 1965Jul 28, 1970Gen ElectricLaminar membrane fuel cells and processes for their manufacture
US3615948 *Dec 27, 1967Oct 26, 1971Wolfgang P KrostewitzConcentration fuel cell
US3977901 *Oct 23, 1974Aug 31, 1976Westinghouse Electric CorporationMetal/air cells and improved air electrodes for use therein
US4390603 *May 21, 1982Jun 28, 1983Hitachi, Ltd.Methanol fuel cell
US4443522 *May 17, 1982Apr 17, 1984Struthers Ralph CMetal/acid ion permeable membrane fuel cell
US4562123 *Sep 12, 1984Dec 31, 1985Hitachi, Ltd.Liquid fuel cell
US4664761 *Dec 27, 1985May 12, 1987Uop Inc.Electrochemical method and apparatus using proton-conducting polymers
US4783381 *Jul 9, 1987Nov 8, 1988Interox (Societe Anonyme)Process for the production of electricity in a fuel cell, and fuel cell
US4810485 *Oct 23, 1987Mar 7, 1989Institute Of Gas TechnologyHydrogen forming reaction process
US4828941 *May 19, 1987May 9, 1989Basf AktiengesellschaftMethanol/air fuel cells
US4894301 *Aug 3, 1989Jan 16, 1990Bell Communications Research, Inc.Battery containing solid protonically conducting electrolyte
US4948680 *May 20, 1988Aug 14, 1990Sri InternationalSolid compositions for fuel cell electrolytes
US4981763 *Nov 20, 1989Jan 1, 1991Mitsubishi Denki Kabushiki KaishaElectrochemical single battery and method for producing the same
US4988582 *May 4, 1990Jan 29, 1991Bell Communications Research, Inc.Compact fuel cell and continuous process for making the cell
US4988583 *Aug 30, 1989Jan 29, 1991Her Majesty The Queen As Represented By The Minister Of National Defence Of Her Majesty's Canadian GovernmentNovel fuel cell fluid flow field plate
US5102750 *Dec 18, 1990Apr 7, 1992Bell Communications Research, Inc.Efficiency enhancement for solid-electrolyte fuel cell
US5132193 *Mar 7, 1991Jul 21, 1992Physical Sciences, Inc.Generation of electricity with fuel cell using alcohol fuel
US5139541 *Jul 22, 1991Aug 18, 1992Bend Research, Inc.Hydrogen-permeable composite metal membrane
US5141604 *Dec 8, 1989Aug 25, 1992Electron Transfer Technologies, Inc.Dehydrogenation reaction utilizing mobile atom transmissive membrane
US5162166 *Jul 19, 1991Nov 10, 1992Kerr-Mcgee CorporationDevices providing electrical energy from fuel/oxygen mixtures
US5183549 *Jan 26, 1990Feb 2, 1993Commtech International Management CorporationMulti-analyte sensing electrolytic cell
US5252410 *Sep 13, 1991Oct 12, 1993Ballard Power Systems Inc.Lightweight fuel cell membrane electrode assembly with integral reactant flow passages
US5272017 *Apr 3, 1992Dec 21, 1993General Motors CorporationMembrane-electrode assemblies for electrochemical cells
US5318863 *Feb 26, 1993Jun 7, 1994Bcs Technology, Inc.Near ambient, unhumidified solid polymer fuel cell
US5350643 *Jun 1, 1993Sep 27, 1994Hitachi, Ltd.Solid polymer electrolyte type fuel cell
US5372896 *Sep 20, 1993Dec 13, 1994The United States Of America As Represented By The Secretary Of The ArmyTreated solid polymer electrolyte membrane for use in a fuel cell and fuel cell including the treated solid polymer electrolyte membrane
Non-Patent Citations
Reference
1 *Appleby, A.J., and F.R. Foulkes, Fuel Cell Handbook , Krieger Publishing Co., Malabar, FL, 1993, Chapters 8, 10, 11, 12, 13, 16.
2Appleby, A.J., and F.R. Foulkes, Fuel Cell Handbook, Krieger Publishing Co., Malabar, FL, 1993, Chapters 8, 10, 11, 12, 13, 16.
3 *Appleby, A.J., and Foulkes, F.R., Fuel Cell Handbook , Cathodic Electrocatalysis , Krieger Publishing Co., Malabar, FL, pp. 405 406.
4 *Appleby, A.J., and Foulkes, F.R., Fuel Cell Handbook , Electrolytes , Krieger Publishing Co., Malabar, FL, Chapter 10, pp. 263 265.
5Appleby, A.J., and Foulkes, F.R., Fuel Cell Handbook, "Cathodic Electrocatalysis", Krieger Publishing Co., Malabar, FL, pp. 405-406.
6Appleby, A.J., and Foulkes, F.R., Fuel Cell Handbook, "Electrolytes", Krieger Publishing Co., Malabar, FL, Chapter 10, pp. 263-265.
7 *Fuel Cell Systems , (Eds. Blomen, L.J.M.J., and Mugerwa, M.N.), Plenum Press, New York, 1993, Chapter 2: pp. 42 52, 63 69, Chapter 3: pp. 88 97, p. 110, Chapters 7, 8, 11.
8Fuel Cell Systems, (Eds. Blomen, L.J.M.J., and Mugerwa, M.N.), Plenum Press, New York, 1993, Chapter 2: pp. 42-52, 63-69, Chapter 3: pp. 88-97, p. 110, Chapters 7, 8, 11.
9Hirchenhofer, J.H., Stauffer, D.B., and Engleman, R.R., Fuel Cells -- A Handbook (Revision 3) DOE/METC--94/1006, Jan. 1994, pp. 6-10 to 6-17.
10 *Hirchenhofer, J.H., Stauffer, D.B., and Engleman, R.R., Fuel Cells A Handbook (Revision 3) DOE/METC 94/1006, Jan. 1994, pp. 6 10 to 6 17.
11 *Quantitative Chemical Analysis , Chromatographic Methods and Capillary Electrophoresis , (Daniel C. Harris), 4th Edition, 1982.
12Quantitative Chemical Analysis, "Chromatographic Methods and Capillary Electrophoresis", (Daniel C. Harris), 4th Edition, 1982.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6376113Nov 12, 1998Apr 23, 2002Idatech, LlcIntegrated fuel cell system
US6436566Jun 29, 2000Aug 20, 2002Toyota Jidosha Kabushiki KaishaFuel cell and polymer electrolyte membrane
US6495277Jul 26, 2000Dec 17, 2002Idatech, LlcFuel cell system controller
US6534210Jan 16, 2001Mar 18, 2003Visteon Global Technologies, Inc.Auxiliary convective fuel cell stacks for fuel cell power generation systems
US6554877Jan 3, 2001Apr 29, 2003More Energy Ltd.Liquid fuel compositions for electrochemical fuel cells
US6667128Jun 1, 2001Dec 23, 2003Idatech, LlcFuel cells and fuel cell systems containing non-aqueous electrolytes
US6686077 *Nov 21, 2001Feb 3, 2004The Boeing CompanyLiquid hetero-interface fuel cell device
US6758871Nov 20, 2002Jul 6, 2004More Energy Ltd.Liquid fuel compositions for electrochemical fuel cells
US6770186Nov 13, 2001Aug 3, 2004Eldat Communication Ltd.Rechargeable hydrogen-fueled motor vehicle
US6773470Aug 29, 2002Aug 10, 2004More Energy Ltd.Suspensions for use as fuel for electrochemical fuel cells
US6858341May 21, 2002Feb 22, 2005Idatech, LlcBipolar plate assembly, fuel cell stacks and fuel cell systems incorporating the same
US6890675Mar 27, 2001May 10, 2005Manhattan Scientifics, Inc.Method of operating a fuel cell system, and fuel cell system operable accordingly
US6979507Nov 25, 2002Dec 27, 2005Idatech, LlcFuel cell system controller
US7074509Nov 13, 2001Jul 11, 2006Eldat Communication Ltd.Hydrogen generators for fuel cells
US7147677Nov 30, 2004Dec 12, 2006Idatech, LlcBipolar plate assembly, fuel cell stacks and fuel cell systems incorporating the same
US7258946Dec 22, 2003Aug 21, 2007Idatech, LlcFuel cells and fuel cell systems containing non-aqueous electrolytes
US7371481Jun 13, 2005May 13, 2008Hewlett-Packard Development Company, L.P.Electrode having macropores and micropores therein
US7435505 *Aug 12, 2002Oct 14, 2008Sfc Smart Fuel Cell AgFuel cell combination
US7491462Aug 18, 2003Feb 17, 2009Toyota Jidosha Kabushiki KaishaElectrolyte membrane for fuel cell operable in medium temperature range, fuel cell using the same, and manufacturing methods therefor
US7744761Jun 27, 2008Jun 29, 2010Calera CorporationDesalination methods and systems that include carbonate compound precipitation
US7749476Jul 6, 2010Calera CorporationProduction of carbonate-containing compositions from material comprising metal silicates
US7753618May 29, 2009Jul 13, 2010Calera CorporationRocks and aggregate, and methods of making and using the same
US7754169Jul 13, 2010Calera CorporationMethods and systems for utilizing waste sources of metal oxides
US7771684Sep 30, 2009Aug 10, 2010Calera CorporationCO2-sequestering formed building materials
US7790012Dec 23, 2008Sep 7, 2010Calera CorporationLow energy electrochemical hydroxide system and method
US7807305Oct 26, 2006Oct 5, 2010Andrei LeonidaFuel cell system suitable for complex fuels and a method of operation of the same
US7815880Oct 22, 2009Oct 19, 2010Calera CorporationReduced-carbon footprint concrete compositions
US7829053Nov 9, 2010Calera CorporationNon-cementitious compositions comprising CO2 sequestering additives
US7842428Nov 30, 2010Idatech, LlcConsumption-based fuel cell monitoring and control
US7846569Dec 7, 2010Idatech, LlcMethods for operating a fuel cell system under reduced load conditions
US7875163Jun 24, 2009Jan 25, 2011Calera CorporationLow energy 4-cell electrochemical system with carbon dioxide gas
US7887694Feb 15, 2011Calera CorporationMethods of sequestering CO2
US7887958Feb 15, 2011Idatech, LlcHydrogen-producing fuel cell systems with load-responsive feedstock delivery systems
US7914685Jun 4, 2010Mar 29, 2011Calera CorporationRocks and aggregate, and methods of making and using the same
US7923165 *Apr 12, 2011Nuvant Systems, LlcElectrolyte components for use in fuel cells
US7931809Apr 26, 2011Calera CorporationDesalination methods and systems that include carbonate compound precipitation
US7935456May 3, 2011Andrei LeonidaFluid conduit for an electrochemical cell and method of assembling the same
US7939336May 10, 2011Calera CorporationCompositions and methods using substances containing carbon
US7966250Jun 21, 2011Calera CorporationCO2 commodity trading system and method
US7985510Apr 18, 2005Jul 26, 2011Idatech, LlcUtilization-based fuel cell monitoring and control
US7993500Aug 13, 2009Aug 9, 2011Calera CorporationGas diffusion anode and CO2 cathode electrolyte system
US7993511Nov 12, 2009Aug 9, 2011Calera CorporationElectrochemical production of an alkaline solution using CO2
US8006446Jun 29, 2010Aug 30, 2011Calera CorporationCO2-sequestering formed building materials
US8071242May 23, 2006Dec 6, 2011Eldat Communication Ltd.Hydrogen generators for fuel cells
US8133626Dec 3, 2010Mar 13, 2012Idatech, LlcFuel cell system controller
US8137444Mar 10, 2010Mar 20, 2012Calera CorporationSystems and methods for processing CO2
US8277997Jul 29, 2004Oct 2, 2012Idatech, LlcShared variable-based fuel cell system control
US8333944Dec 18, 2012Calera CorporationMethods of sequestering CO2
US8357270Jan 22, 2013Calera CorporationCO2 utilization in electrochemical systems
US8431100Apr 30, 2013Calera CorporationCO2-sequestering formed building materials
US8470275Jul 19, 2010Jun 25, 2013Calera CorporationReduced-carbon footprint concrete compositions
US8491858Oct 5, 2011Jul 23, 2013Calera CorporationGas stream multi-pollutants control systems and methods
US8563188Mar 7, 2012Oct 22, 2013Idatech, LlcFuel cell system controller
US8603424Oct 11, 2012Dec 10, 2013Calera CorporationCO2-sequestering formed building materials
US8834688Feb 10, 2010Sep 16, 2014Calera CorporationLow-voltage alkaline production using hydrogen and electrocatalytic electrodes
US8869477Oct 31, 2011Oct 28, 2014Calera CorporationFormed building materials
US8883104Mar 2, 2010Nov 11, 2014Calera CorporationGas stream multi-pollutants control systems and methods
US8894830Jul 3, 2012Nov 25, 2014Celera CorporationCO2 utilization in electrochemical systems
US9133581Mar 14, 2013Sep 15, 2015Calera CorporationNon-cementitious compositions comprising vaterite and methods thereof
US9260314May 6, 2013Feb 16, 2016Calera CorporationMethods and systems for utilizing waste sources of metal oxides
US9267211Jun 30, 2014Feb 23, 2016Calera CorporationLow-voltage alkaline production using hydrogen and electrocatalytic electrodes
US20020031695 *Jun 26, 2001Mar 14, 2002Smotkin Eugene S.Hydrogen permeable membrane for use in fuel cells, and partial reformate fuel cell system having reforming catalysts in the anode fuel cell compartment
US20030008199 *Aug 28, 2002Jan 9, 2003Medis El Ltd.Class of electrocatalysts and a gas diffusion electrode based thereon
US20030113601 *Nov 25, 2002Jun 19, 2003Edlund David J.Fuel cell system controller
US20030219639 *May 21, 2002Nov 27, 2003Edlund David J.Bipolar plate assembly, fuel cell stacks and fuel cell systems incorporating the same
US20040043277 *Aug 18, 2003Mar 4, 2004Toyota Jidosha Kabushiki KaishaElectrolyte membrane for fuel cell operable in medium temperature range, fuel cell using the same, and manufacturing methods therefor
US20040137312 *Dec 22, 2003Jul 15, 2004Edlund David JFuel cells and fuel cell systems containing non-aqueous electrolytes
US20040253495 *Jun 11, 2003Dec 16, 2004Laven ArneFuel cell device condition detection
US20050026180 *Apr 15, 2004Feb 3, 2005The Board Of Trustees Of The Leland Stanford Junior UniversityDirect multiplex characterization of genomic DNA
US20050069757 *Aug 12, 2002Mar 31, 2005Manfred StefenerFuel cell combination
US20050155279 *Jan 16, 2004Jul 21, 2005Gennadi FinkelshtainStorage-stable fuel concentrate
US20050214624 *Nov 30, 2004Sep 29, 2005Edlund David JBipolar plate assembly, fuel cell stacks and fuel cell systems incorporating the same
US20060093890 *Oct 28, 2005May 4, 2006Steinbroner Matthew PFuel cell stack compression systems, and fuel cell stacks and fuel cell systems incorporating the same
US20060134473 *Dec 21, 2005Jun 22, 2006Edlund David JFuel cell system controller
US20060183008 *Apr 10, 2006Aug 17, 2006More Energy Ltd.Liquid fuel compositions for electrochemical fuel cells
US20060207165 *Apr 10, 2006Sep 21, 2006More Energy Ltd.Suspensions for use as fuel for electrochemical fuel cells
US20060280996 *Jun 13, 2005Dec 14, 2006Mittelstadt Laurie SElectrode having macropores and micropores therein
US20070059582 *Sep 6, 2006Mar 15, 2007Andrei LeonidaFluid conduit for an electrochemical cell and method of assembling the same
US20070099062 *Oct 26, 2006May 3, 2007Andrei LeonidaFuel cell system suitable for complex fuels and a method of operation of the same
US20070259236 *Aug 11, 2006Nov 8, 2007Lang Christopher MAnionic fuel cells, hybrid fuel cells, and methods of fabrication thereof
US20080057381 *Sep 5, 2006Mar 6, 2008Jang Bor ZDissolved-fuel direct alcohol fuel cell
US20080124605 *Nov 28, 2005May 29, 2008Toyota Jidosha Kabushiki KaishaSolid Electrolyte And Manufacturing Method Of The Same
US20090169452 *Dec 24, 2008Jul 2, 2009Constantz Brent RMethods of sequestering co2
US20100028736 *Aug 1, 2009Feb 4, 2010Georgia Tech Research CorporationHybrid Ionomer Electrochemical Devices
US20110151349 *Jun 10, 2009Jun 23, 2011Technion Research & Development Foundation Ltd.Double-electrolyte fuel-cell
CN1306642C *Jul 10, 2003Mar 21, 2007通用电气公司Fused hydride fuel cell
CN100454634CAug 20, 2004Jan 21, 2009中国科学院大连化学物理研究所Proton exchange membrane of direct alcohol fuel cell and method for preparing membrane electrode
EP1073140A1 *Jun 28, 2000Jan 31, 2001Toyota Jidosha Kabushiki KaishaFuel cell and polymer electrolyte membrane
EP1383196A2 *Jul 10, 2003Jan 21, 2004General Electric CompanyMolten hydride fuel cell (MHFC)
EP1394884A2 *Aug 27, 2003Mar 3, 2004Toyota Jidosha Kabushiki KaishaElectrolyte membrane for fuel cell operable in medium temperature range, fuel cell using the same, and manufacturing methods therefor
WO2002011226A2 *Jun 22, 2001Feb 7, 2002Nuvant Systems, Inc.Hydrogen permeable membrane for use in fuel cells, and partial reformate fuel cell system having reforming catalysts in the anode fuel cell compartment
WO2002011226A3 *Jun 22, 2001Nov 20, 2003Nuvant Systems IncHydrogen permeable membrane for use in fuel cells, and partial reformate fuel cell system having reforming catalysts in the anode fuel cell compartment
WO2008054858A3 *Apr 18, 2007Jul 31, 2008Georgia Tech Res InstAnionic fuel cells, hybrid fuel cells, and methods of fabrication thereof
WO2010074687A1 *Dec 23, 2008Jul 1, 2010Calera CorporationLow-energy electrochemical proton transfer system and method
Classifications
U.S. Classification429/500, 429/516
International ClassificationH01M8/02, H01M8/00, H01M8/08
Cooperative ClassificationH01M8/0291, H01M8/00, Y02E60/50, H01M8/0293, H01M8/08, H01M2300/0082
European ClassificationH01M8/02E2, H01M8/08, H01M8/00
Legal Events
DateCodeEventDescription
Apr 4, 1996ASAssignment
Owner name: ILLINOIS INSTITUTE OF TECHNOLOGY, ILLINOIS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SMOTKIN, EUGENE S.;MALLOUK, THOMAS E.;WARD, MICHAEL D.;AND OTHERS;REEL/FRAME:007874/0283
Effective date: 19960206
May 24, 2002FPAYFee payment
Year of fee payment: 4
Jun 28, 2006REMIMaintenance fee reminder mailed
Dec 8, 2006LAPSLapse for failure to pay maintenance fees
Feb 6, 2007FPExpired due to failure to pay maintenance fee
Effective date: 20061208